well, dei (directed) has seperate channels for each of the buttons. button 1 is channel 1, button 2 channel 2, etc. now pressing 2 buttons at the same time activates different channels as well...but it also depends on the model. for example, buttons one and 2 activate channel 5. now if your specifc brain does not support these channels or the wires are not hooked up, then well...it wont work. if the wires are hooked up then the pulse coming from the alarm brain may not have enough current to activate whatever it is you are trying to activate. use a relay.

have a nice day and get rid of your negitive reps